The mid-depth circulation of the subpolar North Atlantic Ocean as measured by subsurface floats

摘要: The multi-year mean, mid-depth circulation of the subpolar North Atlantic Ocean was estimated from direct velocity measurements obtained over a 7.5-year period by 211 neutrally-buoyant, profiling, subsurface floats. We present statistical analysis these drift data, and describe features 400–1500 m depth as measured time-lagged auto-covariances indicate Lagrangian integral time scale approximately 10 days at all depths throughout basin. Space–time averages associated error ellipses were constructed, this information used in an objective to produce estimates mean flow. Estimates eddy kinetic energy also computed. mapped flow depicts basin-scale cyclonic gyre bounded south Current. strongest currents are found along coasts Greenland Labrador, where speeds exceed 10cms-1. Closed recirculations appear just offshore boundary Labrador Irminger Seas Iceland basin, southwest Reykjanes Ridge. Topographic steering extends upwards least 400 m above bathymetry that is significantly deeper, most apparent basin boundaries, around Ridge, through gaps Mid-Atlantic In center Current characteristically weak with few large-scale features. There no indication strong linkage western subtropical sampled